Help: i have a problem with my plextor 16/10/40A

[K-And]

I just bought a plex writer have installed it into my system. However i have a suspicion that something is very wrong.
My first suspicion is that whenever there is a cd in the drive the drive light is ALWAYS turned on, and i mean always.
I have a strong feeling that this is related to the many lockups of my computer, when im trying to read a cd. The lockups havent been consistent though, and i have in fact burned a cd.
i have tried to move the writer around from IDE1 to IDE0 and switching it from slave to master and so on, but no luck.

my system is
Mobo = asus K7M AMD 751 chipset
cpu=700 athlon
ram=128 pc100
graphics card, Geforce 256 ddr
soundcard=soundblaster AWE 64

plz respond